Super helpful, thanks! The NumPy page on the migration has some details on the differences:
> ... [Here] are the numpy.distutils features that are not present in setuptools:
* Nested setup.py files
* Fortran build support
* BLAS/LAPACK library support (OpenBLAS, MKL, ATLAS, Netlib LAPACK/BLAS, BLIS, 64-bit ILP interface, etc.)
* Support for a few other scientific libraries, like FFTW and UMFPACK
* Better MinGW support
* Per-compiler build flag customization (e.g. -O3 and SSE2 flags are default)
* a simple user build config system, see site.cfg.example
* SIMD intrinsics support
* Support for the NumPy-specific .src templating format for .c/.h files
https://numpy.org/doc/stable/reference/distutils_status_migr...